Method of starting internal-combustion engines



May 12, 1925. 1,537,128

R. MAYER METHOD OF STARTING INTERNAL COMBUSTION ENGINES Filed Aug. 24.1921 11v VENTOR A To/m5 Y6 Patented May 1;, 1925.

.UNlTED STATES PATENT OFFICE.

RUDOLF MAYER, OF GOLDSCHMIEDEN KREIS, BRESLAU, GERMANY, ASSIGNOR TO THEFIRM OF MASCHINENFABRIK AUGSBURG-NUERNBURG, AKTIENGESELLSCHAFT, OFAUGSBURG, GERMANY, A GERMAN CORPORATION.

neuron of srraa'rrne INTERNALCOMBUSTION enemas.

Application filed August 24, 1921/ Serial No. 494,930.

enanrnn uunnn THE raovrsroxs or run ACT or MARCH 3, 1921, 41 sun I..,-1313.

T allwhom it may concern:

Be it known that I, RUnoLr MAYER, a citizen of Germany, residing at-Linden Str., Goldschmieden Kr., Breslau, Germany, have invented certainnew and useful Improvements in Methods of Starting Internal- CombustionEngines (for which I have filed application in Germany, July 5, 1915),of which the following is a specification.

The present invention relates to a method of'starting internalcombustion engines of the type in which ignition iseffected by means ofthe high temperature attained in the cylinder during the compressionstroke, and in which'the products of combustion are expelled from thecylinder'by an inrush of air.

It is common in engines of this type to provide means for cooling thescavenging air during the operation of the engine for the purpose ofincreasing the wei ht of air which is compressed at each strolre of thepiston, or starting the engine, however,

when the parts are cold, it is usually necesea that the scavenging airbe heated in or er to generate a temperature sufiiciently high to causeignition.

It is accordingly a principal object of the present invention to providea method for starting engines of the above type in which the air passingto the cylinder 1s heated during the starting period and is normallycooled during the time when the engine is in operation.

More specifically it is an object of the invention to utilize the samemeans which are provided to normally cool the scavenging air for thepurpose of heating such air during the starting period. The entiresystem is thus rendered simple and accessible, since only a singleunitary apparatus is required for heating and for cooling the scavenginga1r. v In the accompanying drawing, which is a view largelydiagrammatic, I have illustrated by way of example a preferredembodiment of apparatus for carrying one my improved method. I

In the said drawing (1 indicates the pump employed for compressin thescavenging air drawn from the atmosp are or other con venient sourcethrough a feed pipe 6, and

passing it at any desired compression through the heat exchanger 6 intothe reservoid 9, from which it may be supplied to the internalcombustion engine as required. The heat exchanger 72 may be of any wellknown type containing two fluid passages'having leak-proof connectionsbetween them.

During the startin period of the engine.

when it is desirable t at the scavenging air be heated, steam issupplied to the heating space of the exchanger 12 through the line aleading from a steam main or other convenient supply. In the line athere is provided a three-way valve d which may be turned to admit steamto the heat exchanger or which may be turned to permit a flow from theline 7' into the exchanger 6, the line f being connected with a supplyof cold water or other cooling medium for use in cooling the air duringnormal operation of the engine. When the engine is first started valve dis turned to the position shown, in which case steam will be admitted tothe heat exchanger 6 and will warm theair on its way to the engine. Assoon as the engine begins to operate satisfactorily under its own power,the valve 12 is turned 90 in the direction indicated by the arrow, inwhich position it will shut ofi the flow of steam and will permit thecooling fluid to circulate through the ex changer b.

It is to be understood that any convenient fluid having a temperaturematerially higher than that of the air passing to the reservoir 9 may beemployed as a heating medium, for instance, hot water, hot gases such asflue gases, and the like. Likewise any convenient cooling fluid otherthan cold water may be em loyed if desired. I have illustrated apreierred embodiment of the apparatus for carrying out my improvedmethod, but it is to be understood that the apparatus may be variouslyconstructed to carr out my invention as defined in the appen ed claims.I claim: a a

i 1'. In the operation of Diesel engines of the two-cycle type, -inwhich. air under pressure is introduced into the cylinder to scavengethe cylinder and to furnish the charge of air for combustion, themethodwhich comprises the steps of'heating the scavenging air before admissionto the engine cylinder, and subsequently cooling said air after theengine begins to operate under its own power.

2. I11 the operation of Diesel engines of the two-cycle type, in whichair under pressure is introduced into the cylinder to scavenge thecylinder and to furnish the charge of air for combustion, the methodwhich comprises the steps of heating the scavenging air before admissionto the engine cylinder, and simultaneously discontinuing said heatingand efiecting a material cooling of said air after the engine begins tooperate under its own power.

3. In the operation of Diesel engines of the two-cycle type, in whichair under pressure is introduced into the cylinder to scav enge thecylinder and to furnish the charge of air for combustion, the methodwhich comprises the steps of passing a heating medium into heatexchanging proximity with the scavenging air on its Way to the enginecylinder, and replacing said heating medium by a cooling medium afterthe engine begins to operate under its own power.

4. In a method for starting internal combustion engines whose scavengingair is normally cooled during the operation of the engine, the step oftemporarily passing a heating medium in heat exchanging proximity withsaid air along the same course normally traversed by the cooling medium.

5. In a starting system for internal combustion engines, a compressorfor supplying air to the engine cylinder at a pressure aboveatmospheric, 2. heat exchanger interposed between said compressor andsaid cylinder, said heat exchanger having a passage for conveying theair discharged from said compressor, and nieans for supplying said heatexchanger successively with a heating medium and with a cooling medium.

6. In a Diesel engine, a compressor for supplying air to the enginecylnder at a pressure above atmospheric, a heat exchanger interposedbetween said compressor and said cylinder, said heat exchanger having apassage for conveying the air dis? charged from said compressor, meansfor supplying extraneous heat to said heat exchanger during the startingof the engine, and means for supplying a cooling medium to said heatexchanger during normal operation of the engine.

In testimony whereof I aflix my signature.

RUDOLF MAYER.

